Light-channeling apparatus

ABSTRACT

A light-channeling apparatus for a scanning module is provided. The scanning module uses a first light-guiding tube to channel light from a light source to a scanning region and uses a second light-guiding tube to channel light reflected from the scanning region to a light passage slit on the body casing of the scanning module. As a result, very little light from the light source is dispersed and external light is kept out from the transmission pathway.

BACKGROUND OF INVENTION

[0001] 1. Field of Invention

[0002] The present invention relates to a light-channeling apparatus.More particularly, the present invention relates to a light-channelingtube capable of preventing light dispersion and shielding againstoutside sources of light interference.

[0003] 2. Description of Related Art

[0004] Following the rapid progress in computer capability and thedevelopment of Internet and multimedia technologies, the transmission ofdocuments and images has become an essential element in communication.Textual information or image patterns are captured by a peripheraldevice such as an optical scanner and then converted into digital databy an analogue/digital converter. The digital data is transferred to animage file that can be displayed, identified, edited, stored or output.

[0005] In general for a scanning system, the light source and the firstreflecting mirror of a scanning module are exposed outside a scanningmodule and hence this is one of the major factors that affect scanquality. In other words, most of the light from a light source projectedonto a document must be redirected onto the scanning region afterreflection and the document image must be shielded against interferencefrom external light sources so that the image is able to project ontothe first reflecting mirror. Both are critical factors that determinethe ultimate quality of the image as captured by the scanner. FIG. 1 isa schematic diagram showing the position of a light source 120 and afirst reflection mirror 130 inside a conventional scanning module 100.As shown in FIG. 1, the light source 120 is installed inside a lightsource carrier 118 on a body casing 110. The first reflecting mirror130, a second reflecting mirror 132, a third reflecting mirror 134, alens 140 and a light-sensing device 150 is are enclosed inside the bodycasing 110. Viewed from the top, the light source 120 and the firstreflecting mirror 130 underneath light passage slit 112 can be easilyseen. The light source 120 is, for example, a daylight lamp having along edge similar in length to a document 160. The slit 112 has asufficient width that permits light reflected from the document 160 toproject onto the first reflecting mirror.

[0006] The light source 120 must project a line of light onto thedocument 160 to form a scan line there. To prevent the dispersion oflight, most scanning systemshas have a collimating lens 122 installedabove the light source 120 so that light from the light source 120 isfocused on the document 160 to form an intense scan line. Although thelens 122 focuses light from the light source 120, there is no guaranteethat light will not be dispersed to the surrounding regions.

[0007] Similarly, there is no facilities facility around the slit 112that prevents stray lights from external sources from projecting ontothe first reflecting mirror 130 and interfering with the quality of thereflected light coming from the document 160. Ultimately, quality of theimage may be affected.

SUMMARY OF INVENTION

[0008] Accordingly, one object of the present invention is to provide alight-channeling apparatus for guiding light from a light source to adocument with very little dispersion and guiding the reflected lightfrom the document through a passage slit onto a first reflecting mirrorinside a body casing such that very little stray lights from externalsources are is permitted entry into the body casing.

[0009] To achieve these and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, theinvention provides a light-channeling apparatus for a scanning module.The scanning module includes a light source and a body casing. The bodycasing has a passage slit for light. The light-channeling apparatuscomprises of a first guiding tube and a second guiding tube. The firstguiding tube is connected to the body casing and positioned between thelight source and the document. The second light-guiding tube is alsoconnected to the body casing but positioned between the document and thepassage slit.

[0010] This invention also provides a scanning module for scanning adocument. The scanning module mainly includes a body casing, a lightsource, a plurality of reflecting mirrors, a lens, a light-sensingdevice and a light-channel apparatus. The light source is mounted on thebody casing for illuminating a document. The reflecting mirrors, thelens and the light-sensing device are enclosed inside the body casing.The light-channeling apparatus is connected to the body casing and thatthe light-channeling apparatus comprises of a first light-guiding tubeand a second light-guiding tube. The first light-guiding tube ispositioned between the light source and a document while the secondlight-guiding tube is positioned between the document and a lightpassage slit.

[0011] According to one preferred embodiment of this invention, thelight-guiding tube can be a hollow tube whose interior walls have areflective coating. In addition, a collimating Lens is also installedinside the first light-guiding tube.

[0012] According to another preferred embodiment of this invention, alight-guiding body may be incorporated inside the light-guiding tube.Furthermore, the document end of the first light-guiding tube and thedocument end of the second light-guiding tube may be physicallyconnected together. Moreover, the light-guiding tube and the scanningmodule may be fabricated together as an integrative unit.

[0013] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary, andare intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention. In the drawings,

[0015]FIG. 1 is a schematic diagram showing the position of a lightsource and a first reflection mirror inside a conventional scanningmodule 100;

[0016]FIG. 2 is a schematic diagram showing various components of ascanning module according to one preferred embodiment of this invention;

[0017]FIG. 3 is a cross-sectional view of the interior of alight-channeling apparatus according to one preferred embodiment of thisinvention; and

[0018]FIG. 4 is a perspective view of a light-channel apparatusaccording to one preferred embodiment of this invention.

DETAILED DESCRIPTION

[0019] Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

[0020]FIG. 2 is a schematic diagram showing various components of ascanning module according to one preferred embodiment of this invention.As shown in FIG. 2, the scanning module 200 includes a body casing 110,a light source 120, three reflecting mirrors 130, 132, 134, a lens 140,a light-sensing device 150 and a light-channeling apparatus 210. Thebody casing 110 has a light passage slit 112. The light source 120 ismounted on a carrier base 118 on the body casing 110 for illuminating adocument 160. The reflecting mirrors 130, 132, 134, the lens 140 and thelight-sensing device 150 are all enclosed inside the body casing 110.The light-channeling apparatus 210 is attached to the body casing 110.The light-channeling apparatus 210 comprises of a pair of light-guidingtubes 212 and 218. The light-guiding tube 218 is positioned between thelight source 120 and the document 160 while the light-guiding tube 212is positioned between the document 160 and the slit 112.

[0021] As shown in FIG. 2, the light source 120 projects a beam of lighttowards the document 120. The beam of light reflects from the document160 and enters the body casing 110 through the slit 112. After enteringthe body casing 110, the beam of reflected light projects in sequentialorder onto the first reflecting mirror 130, the second reflecting mirror132 and the third reflecting mirror 134 before arriving at the lens 140.The lens focuses the beam onto the light-sensing device 150.

[0022] The light-guiding tubes 212, 218 have a hollow tube structure.When light from the light source 120 travels to the document 160, thelight-guiding tube 218 focuses the beam of light on the document 160 andhence increases the luminance of the light beam. The light-guiding tube212 channels the beam of reflected light from the document to the slit112 before impinging upon the first reflecting mirror 130 inside thebody casing 110. With this arrangement, very little light is dispersedand interference by strayed lights from external light sources isminimized.

[0023]FIG. 3 is a cross-sectional view of the interior of alight-channeling apparatus according to one preferred embodiment of thisinvention. To optimize the effects provided by the light-guiding tubes212 and 218, a collimating lens 122 is installed inside thelight-guiding tube 218 and the interior sidewalls of both light-guidingtubes 212 and 218 are coated with a reflective layer 216. Obviously, toincrease light-focusing power, a light-guiding body 214 may also beincorporated inside the light-guiding tubes 212 and 218. In other words,the light-guiding tubes not only guide the light beam from the lightsource 120 to the first reflecting mirror 130, but also increase overallluminance level.

[0024]FIG. 4 is a perspective view of a light-channel apparatusaccording to one preferred embodiment of this invention. One end of thelight-guiding tubes 212 and 218 may be connected together to form thelight-channeling apparatus 210 as shown in FIG. 4. In other words, thedocument end of the light-guiding tube 218 and the document end of thelight-guiding tube 212 are joined together to facilitate installation.However, the light-guiding tubes and the scanning module may befabricated together as an integrative unit to reduce production cost.

[0025] In summary, major advantages of the scanning module of thisinvention includes:

[0026] 1. The light-guiding tube of the light-channel apparatus focuseslight from the light source on the document with a greater intensity.

[0027] 2. The light-guiding tube of the light-channel apparatus alsofocuses the light reflected from the document through a slit into thebody casing.

[0028] 3. The scanning module is able to screen out unwantedinterference from external light sources without incurring too muchcost.

[0029] It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

1. A light-channeling apparatus for a scanning module having a lightsource and a body casing, wherein the body casing has a light passageslit, the light-channeling apparatus comprising: a first light-guidingtube attached to the body casing, wherein the first light-guiding tubeis positioned between the light source and a document; and a secondlight-guiding tube attached to the body casing, wherein the secondlight-guiding tube is positioned between the document and the lightpassage slit.
 2. The light-channeling apparatus of claim 1, wherein theinterior sidewalls of the first light-guiding tube has have a reflectivecoating.
 3. The light-channeling apparatus of claim 1, wherein theinterior sidewalls of the second light-guiding tube has have areflective coating.
 4. The light-channeling apparatus of claim 1,wherein the apparatus further includes a light-guiding body inside thefirst light-guiding tube.
 5. The light-channeling apparatus of claim 1,wherein the apparatus further includes a light-guiding body inside thesecond light-guiding tube.
 6. The light-channeling apparatus of claim 1,wherein the first light-guiding tube has a hollow interior.
 7. Thelight-channeling apparatus of claim 1, wherein the second light-guidingtube has a hollow interior.
 8. The light-channeling apparatus of claim1, wherein the apparatus further includes a collimating lens inside thefirst light-guiding tube.
 9. The light-channeling apparatus of claim 1,wherein the document end of the first light-guiding tube and thedocument end of the second light-guiding tube are fused together. 10.The light-channeling apparatus of claim 1, wherein the firstlight-guiding tube and the scanning module are fabricated together as anintegrative unit.
 11. The light-channeling apparatus of claim 1, whereinthe second light-guiding tube and the scanning module are fabricatedtogether as an integrative unit.
 12. A scanning module for scanning adocument, comprising: a body casing having a light passage slit thereon;a light source attached to the body casing; a plurality of reflectingmirrors inside the body casing; a lens inside the body casing; alight-sensing device inside the body casing; and a light-channelingapparatus joined to the body casing, wherein the light-channelingapparatus includes a first light-guiding tube and a second light-guidingtube such that the first light-guiding tube is positioned between thelight source and the document and the second light-guiding tube ispositioned between the document and the light passage slit.
 13. Thescanning module of claim 12, wherein the interior sidewalls of the firstlight-guiding tube has have a reflective coating.
 14. The scanningmodule of claim 12, wherein the interior sidewalls of the secondlight-guiding tube has have a reflective coating.
 15. The scanningmodule of claim 12, wherein the module further includes a light-guidingbody inside the first light-guiding tube.
 16. The scanning module ofclaim 12, wherein the module further includes a light-guiding bodyinside the second light-guiding tube.
 17. The scanning module of claim12, wherein the first light-guiding tube has a hollow interior.
 18. Thescanning module of claim 12, wherein the second light-guiding tube has ahollow interior.
 19. The scanning module of claim 12, wherein the modulefurther includes a collimating lens inside the first light-guiding tube.20. The scanning module of claim 12, wherein the document end of thefirst light-guiding tube and the document end of the secondlight-guiding tube are fused together.
 21. The scanning module of claim12, wherein the first light-guiding tube and the body casing arefabricated together as an integrative unit.
 22. The scanning module ofclaim 12, wherein the second light-guiding tube and the body casing arefabricated together as an integrative unit.